Radio dial mechanism



Dec. 3, 1935.

L. F. CURTIS ET AL RADIO DIAL MECHANISM Filed Oct. l, 1935 2 sheets-sheet 1 l ENTORS @M 4. @www ATTORNEY.

Dec. 3, 1935. F CURTls AL I 2,023,005

RADIO DIAL MECHANISM Filed Oct. l, 1935 2 Sheets-Sheet 2 ATTORNEY.

Patented Dec. 3, 1935 UNITED STATES PATENT OFFICE RADIO DIAL MECHANISM Leslie F. Curtis and Kenneth L. Henderson,

Springfield, Mass., assignors to United American Bosch Corporation, Springfield, Mass., a corporation of New York This invention relates to radio tuning dials,

n and more particularly to illuminated dials bearing a plurality of frequency band scales. In the past there has been great difficulty in recording the exact dial setting of a station on the higher frequency bands. Requirements of pleasing cabinet design and esthetic appearance have necessitated dial scales which were too small and which had inadequate division marks for the higher frequency scales. It quite frequently occurs that many stations are located between two division marks and there is no accurate way of recording the setting for each station. In the invention herein described a novel Vernier indicator is provided which may be read in conjunction withV the main scale to accurately note the exact dial setting for a given station.

An object of this invention is to provide a tuning dial which is more enicient inoperation and more pleasing in appearance.

Another object is to provide a dial which will more accurately indicate the exact setting of a station.

A further object is to provide a multiple frequency band dial which indicates the particular band being used.

Still a further object is to provide an illuminated dial structure in which the lamps are more accessible for replacement.

Other objects and advantages will in part be specifically set forth and in part be obvious when the following specification is read in connection with the accompanying drawings, in which;

Fig. 1 is a front view of the dial and supporting frame; Fig. 2 is a horizontal -section vtaken on line 2-2 of Fig. 1; Fig. 3 is afront view of the driving rdisk, showing the shutter1 and control for the dial mechanism; and Figi'llis a front view of theassembly showing the combined'vernier and masking diskin position.v 1

.'Referringin more detail to Fig. 41, the numeral I indicatesa frame member `of sheet .metalfbeht to form rearwardly extending walls; on all four sides thereof,A andrhavingi` attachingl brackets 2 bent from-.the vertical side walls. f ASupported-iiiterorly against the :front faceof the'frame is a sheetoflglassyretained by' spring clips .4; `asshown inlig.` 2.'` Etched-or otherwiseindented'in the innerface ofthe glassr3 are the-numerals and division-marks of `four separate Afrequency bands.V

Thepnumeralsfand. dial faceare .backed by an opaque material;- with f .the semicircular areas overlying they paths of ,the vvarious lindicators lleft transparent. Aroundmhe periphery of. the dial are the vernier numerals 1 to 59 inclusive and immediately below each of these numerals isla. small pin hole 5 through the opaque material, and through which light is periodically visible in connection with the Vernier action to be explained later. The vertical side walls of the frame I are cut ton allow the strips 6 to be bent out a'nd form supports for the light socket clips l `and lights 8. The light beams enter the edges of the glass 3 and pass laterally through the glass to strike the etched dial numerals, which then 10 'appear as luminous numerals against a dark background and provide a very pleasing appearance.

The dial mechanism is best seen in Fig. 2 and following figures. A driving 'disk 9, having a 15 milled edge, is attached to the condenser shaft Ill of aradio chassis by a hub II which projects from both faces ofthe disk 9. The outer Vface of the driving disk is painted white to obtain maximum lightreection for a reason later ex- 20 plained. A rubber coveredroller I2 bears against the milled edge of diskS l(Fig. 3) and is in turn driven by a metal rollerj`l3 having a milled periphery. The roller I3'is fastened on a shaft I4 which may be drivenl by any suitable tuning 25 knob. One half of a split collar I5 is fastened to the hub II, the other half being attached to the sleeve I6 of a rotatable shutter Il.' The two halves of the split collar I5 are joinedby a coil spring I8. The shutter is'rotatjable to four posi- 30 tions', corresponding tok the vfourfrequency bands of the usual multi-band'receiven and is actuated by the shaft'l9`of a band changing switch through the following means 'A flexible cord 20 is secured at one end to" studsm mounted near `the rim of 35 4rd"4 is passed underthe hub oundvv the eccentric pulley 22 whichisin'ounte on switch shaft I9. From the p`i'1l1ey'f22,` the kcord is trained under the shutter sleeve I6, and over to a stud 23 fastened near 40 thel riniof shutter l.` Four apertures 24,25, 26. and 1 2`lare providedin-the shutter Il (Fig.'3) witlifie'ach backed bya different` coloreditranslucentlxn'mber. anatheentire shutter isnnished -ln black to avoid light reflection. 'I'he showingi 45 angular position due to the action of the cord 20 about the several centers. Frictionally secured to the end of hub Il, infront of the shutter I1, is a black masking disk 28, as shown in Fig. 4. Indicating orices 29, 30, 3l, and 32 are punched in the disk, and twelve equally spaced vernier slots 33 extend radially inward from the periphery.

Operation When the dial is assembled, the masking disk 28 and the frame l are adjusted so that their centers are coincidental. This is accomplished by first rotating masking disk 28 until the indicating orices 29, 30, 3|and 32 are in a horizontal line. The masking disk and the frame are then aligned with respect to the indicating orifices so that the edges 34, 35, 36, and 31 (Fig. 1) of the opaque design on glass 3 bisect the oriiices 30 and 3l in disk 28, and also so that outermost points of orices 29 and 32 in disk 28 are equidistant from the circular edge of the opaque design on glass 3. Then one of the pin holes 5 (Fig. 1) will be illuminated. Upon rotation of the driving disk 9, this pin hole is darkened and one `five points distant is subsequently illuminated, the progression being I-S-lI-IB 56-2-1--12 etc. Approximately two degrees of scale travel results in one revolution of the light spot around the dial. If a ner Vernier action is desired, the masking disk 28 may have any greater number of slots 33 which is evenly divisible into sixty. When sixty slots are provided, each pin hole 5 is illuminated in regular sequence; however, proper assembly adjustment becomes increasingly diiilcult as the skip interval jis reduced.

, When the various dial elements are positioned as shown in Figs. 3 and 4, the hole 24 of shutter I'l will be inalignment with the indicator hole 29 of masking disk 28 and a diamond of colored light will be visible as an indicator on the high frequency or lower scale, as shown in Fig. 1. When the shaft I9 of the wave change switch is turned clockwise, the holesy 25 and 30 will be aligned and indicate the next adjacent scale. Continued clockwise turning will successively align the holes 32--21, and 3|-26, to indicate the remaining two upper scales. Since an illuminated indicator or pointer appears only adjacent the particular scale in use and moves with the rotation of the tuning knob, there can be no uncertainty on the part of the operator as to which 1. In an illuminated radio dial mechanism having a plurality of tuning scales, a driving disk, a hub extending from said driving disk, a masking disk secured to said hub and having a plurality of spaced indicating orifices, a shutter rotatably attached to said hub intermediate said disks and having a plurality of apertures' therein, a flexible cord attached to said driving disk and said shutter, and means for operating said cord, whereby said shutter may be rotated relative to said masking disk to align a shutter aperture with an indicating orifice in said masking disk to produce an indicating light spot on one of said tuning scales.

2. In an illuminated radio dial mechanism having a plurality of tuning scales, a driving disk, a hub extending from said driving disk, a masking disk secured to said hub and having a plurality of indicating orices of different radial spacing, a shutter rotatably attached to said hub intermediate said disks `and having a plurality of apertures therein radially spaced to accord with said indicating orifices, a flexible cord attached to said driving disk and said shutter, and means for operating said cord, whereby -said shutter may be rotated relative to said masking disk to align a shutter aperture with an indicating oriiice in said masking disk to produce an indicating light spot on one of said tuning scales.

3. In an illuminated radio dial mechanism having a plurality of tuning scales, a driving disk, a hub extending from said driving disk, a masking disk secured to said hub and having a plurality of spaced indicating orices, a shutter rotatably attached to said hub intermediate said disks and having a plurality of apertures therein, a spring urging said shutter in one direction, a ilexible cord attached to said driving disk and said shutter, said cord being maintained under tension by said spring-urged shutter, and means for operating said cord, whereby said shutter may be rotated relative to said masking disk to align a shutter aperture with an indicating orifice in said masking disk to produce an indicating light spot on one of said tuning scales.

4. In an illuminated radio dial mechanism having a plurality of tuning scales, a driving disk, a

`hub extending from said driving disk, a maskspringurging said shutter in one direction, a 45 flexible cord attached to said driving disk and `said shutter, said cord being maintained under tension by said spring-urged shutter, a shaft carrying an eccentric pulley, a portion of said lcord trained around said pulley, whereby said shaft may be actuated to rotate said shutter relative to said masking disk to align a shutter aperture withan indicating orifice in said masking disk to produce an indicating light spot on one of 55 said tuning scales.

5. In an illuminated radio dial, a light source, a vernier indicator comprising a plurality of light-transmitting pin holes, a rotatable masking disk positioned intermediate said light-source and said dial, and a plurality of slots in said disk, whereby said slots and said pin holes cooperate to produce a point of light which advances from one pin hole to another upon unidirectional rotation of said masking disk.

6. In an illuminated radio dial, a light source, operating mechanism and an indicator for said dial, a vernier indicator comprising a' marking member positioned intermediate said light source and said dial, a plurality of slots in said member,

and a plurality of pin holes arranged in regular sequence upon said dial, whereby said slots and said pin holes cooperate to produce a. point of light which advances along said pin holes at a speed greater than the speed of said indicator.

7. In an illuminated radio dial,` a light source,

operating mechanism and an indicator for said dial, a Vernier indicator comprising a masking member positioned intermediate said light source and said dial, a plurality of slots in said member,

and a plurality of pin holes arranged in regular sequence upon said dial, the number o1' said pin holes being equal to a number n i 1, and the 

